1. Field of the Invention
The invention relates to a multimode monitor and, more particularly, to an on-screen display device for a multimode monitor that can display frequency and picture control modes on the screen of the multimode monitor in an on-screen display manner, and a method thereof.
2. Description of Related Art
On the one hand, a conventional multimode monitor that indicates a picture control mode that can be changed by a user with a key input of the multimode monitor uses light emitting diodes (LEDs) to display a presently selected picture control mode to the user. The LED display greatly increases the display area required by the multimode monitor, however, and the LEDs indicate only the selected picture control mode and not a fine control, frequency mode, which it also would be desirable to check.
On the other hand, Japanese laid-open patent publication No. sho 63-129788 describes a character generator controlled by a microprocessor and a red, green and blue (RGB) color encoder for superimposing an output signal of the character generator onto a composite video signal to achieve on-screen display of the generated characters on the screen of a television or monitor having a speed multiplication function. A speed multiplying circuit to transform the output signal of the character generator into a signal for speed-multiplied scanning onto the screen is not employed, however, whereby the cost of the product can be reduced desirably.